MIPS: ath79: add common GPIO buttons device

Almost all boards have one or more push buttons connected to GPIO lines.
This patch adds common code to register a platform_device for them.

The patch also adds support for the buttons on the PB44 board.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: Luis R. Rodriguez <lrodriguez@atheros.com>
Cc: Cliff Holden <Cliff.Holden@Atheros.com>
Cc: Kathy Giori <Kathy.Giori@Atheros.com>
Patchwork: https://patchwork.linux-mips.org/patch/1954/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

5 files changed, 113 insertions, 0 deletions

diff --git a/arch/mips/ath79/Kconfig b/arch/mips/ath79/Kconfig
index 5bc480e28b0..185a8d6c73d 100644
--- a/arch/mips/ath79/Kconfig
+++ b/arch/mips/ath79/Kconfig
@@ -5,6 +5,7 @@ menu "Atheros AR71XX/AR724X/AR913X machine selection"
 config ATH79_MACH_PB44
         bool "Atheros PB44 reference board"
         select SOC_AR71XX
+        select ATH79_DEV_GPIO_BUTTONS
         select ATH79_DEV_LEDS_GPIO
         help
           Say 'Y' here if you want your kernel to support the
@@ -21,6 +22,9 @@ config SOC_AR724X
 config SOC_AR913X
         def_bool n
 
+config ATH79_DEV_GPIO_BUTTONS
+        def_bool n
+
 config ATH79_DEV_LEDS_GPIO
         def_bool n
 
diff --git a/arch/mips/ath79/Makefile b/arch/mips/ath79/Makefile
index f41c0296aa2..344e9ab1e10 100644
--- a/arch/mips/ath79/Makefile
+++ b/arch/mips/ath79/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_EARLY_PRINTK)		+= early_printk.o
 # Devices
 #
 obj-y                                   += dev-common.o
+obj-$(CONFIG_ATH79_DEV_GPIO_BUTTONS)    += dev-gpio-buttons.o
 obj-$(CONFIG_ATH79_DEV_LEDS_GPIO)       += dev-leds-gpio.o
 
 #
diff --git a/arch/mips/ath79/dev-gpio-buttons.c b/arch/mips/ath79/dev-gpio-buttons.c
new file mode 100644
index 00000000000..4b0168a11c0
--- /dev/null
+++ b/arch/mips/ath79/dev-gpio-buttons.c
@@ -0,0 +1,58 @@
+/*
+ *  Atheros AR71XX/AR724X/AR913X GPIO button support
+ *
+ *  Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
+ *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ */
+
+#include "linux/init.h"
+#include "linux/slab.h"
+#include <linux/platform_device.h>
+
+#include "dev-gpio-buttons.h"
+
+void __init ath79_register_gpio_keys_polled(int id,
+                                            unsigned poll_interval,
+                                            unsigned nbuttons,
+                                            struct gpio_keys_button *buttons)
+{
+        struct platform_device *pdev;
+        struct gpio_keys_platform_data pdata;
+        struct gpio_keys_button *p;
+        int err;
+
+        p = kmalloc(nbuttons * sizeof(*p), GFP_KERNEL);
+        if (!p)
+                return;
+
+        memcpy(p, buttons, nbuttons * sizeof(*p));
+
+        pdev = platform_device_alloc("gpio-keys-polled", id);
+        if (!pdev)
+                goto err_free_buttons;
+
+        memset(&pdata, 0, sizeof(pdata));
+        pdata.poll_interval = poll_interval;
+        pdata.nbuttons = nbuttons;
+        pdata.buttons = p;
+
+        err = platform_device_add_data(pdev, &pdata, sizeof(pdata));
+        if (err)
+                goto err_put_pdev;
+
+        err = platform_device_add(pdev);
+        if (err)
+                goto err_put_pdev;
+
+        return;
+
+err_put_pdev:
+        platform_device_put(pdev);
+
+err_free_buttons:
+        kfree(p);
+}
diff --git a/arch/mips/ath79/dev-gpio-buttons.h b/arch/mips/ath79/dev-gpio-buttons.h
new file mode 100644
index 00000000000..481847ac1cb
--- /dev/null
+++ b/arch/mips/ath79/dev-gpio-buttons.h
@@ -0,0 +1,23 @@
+/*
+ *  Atheros AR71XX/AR724X/AR913X GPIO button support
+ *
+ *  Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
+ *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ */
+
+#ifndef _ATH79_DEV_GPIO_BUTTONS_H
+#define _ATH79_DEV_GPIO_BUTTONS_H
+
+#include <linux/input.h>
+#include <linux/gpio_keys.h>
+
+void ath79_register_gpio_keys_polled(int id,
+                                     unsigned poll_interval,
+                                     unsigned nbuttons,
+                                     struct gpio_keys_button *buttons);
+
+#endif /* _ATH79_DEV_GPIO_BUTTONS_H */
diff --git a/arch/mips/ath79/mach-pb44.c b/arch/mips/ath79/mach-pb44.c
index e176779af66..3dc5080185c 100644
--- a/arch/mips/ath79/mach-pb44.c
+++ b/arch/mips/ath79/mach-pb44.c
@@ -15,15 +15,21 @@
 #include <linux/i2c/pcf857x.h>
 
 #include "machtypes.h"
+#include "dev-gpio-buttons.h"
 #include "dev-leds-gpio.h"
 
 #define PB44_GPIO_I2C_SCL       0
 #define PB44_GPIO_I2C_SDA       1
 
 #define PB44_GPIO_EXP_BASE      16
+#define PB44_GPIO_SW_RESET      (PB44_GPIO_EXP_BASE + 6)
+#define PB44_GPIO_SW_JUMP       (PB44_GPIO_EXP_BASE + 8)
 #define PB44_GPIO_LED_JUMP1     (PB44_GPIO_EXP_BASE + 9)
 #define PB44_GPIO_LED_JUMP2     (PB44_GPIO_EXP_BASE + 10)
 
+#define PB44_KEYS_POLL_INTERVAL         20      /* msecs */
+#define PB44_KEYS_DEBOUNCE_INTERVAL     (3 * PB44_KEYS_POLL_INTERVAL)
+
 static struct i2c_gpio_platform_data pb44_i2c_gpio_data = {
         .sda_pin        = PB44_GPIO_I2C_SDA,
         .scl_pin        = PB44_GPIO_I2C_SCL,
@@ -60,6 +66,24 @@ static struct gpio_led pb44_leds_gpio[] __initdata = {
         },
 };
 
+static struct gpio_keys_button pb44_gpio_keys[] __initdata = {
+        {
+                .desc           = "soft_reset",
+                .type           = EV_KEY,
+                .code           = KEY_RESTART,
+                .debounce_interval = PB44_KEYS_DEBOUNCE_INTERVAL,
+                .gpio           = PB44_GPIO_SW_RESET,
+                .active_low     = 1,
+        } , {
+                .desc           = "jumpstart",
+                .type           = EV_KEY,
+                .code           = KEY_WPS_BUTTON,
+                .debounce_interval = PB44_KEYS_DEBOUNCE_INTERVAL,
+                .gpio           = PB44_GPIO_SW_JUMP,
+                .active_low     = 1,
+        }
+};
+
 static void __init pb44_init(void)
 {
         i2c_register_board_info(0, pb44_i2c_board_info,
@@ -68,6 +92,9 @@ static void __init pb44_init(void)
 
         ath79_register_leds_gpio(-1, ARRAY_SIZE(pb44_leds_gpio),
                                  pb44_leds_gpio);
+        ath79_register_gpio_keys_polled(-1, PB44_KEYS_POLL_INTERVAL,
+                                        ARRAY_SIZE(pb44_gpio_keys),
+                                        pb44_gpio_keys);
 }
 
 MIPS_MACHINE(ATH79_MACH_PB44, "PB44", "Atheros PB44 reference board",